I am certainly no expert, but I do like to think that I have a fair amount of observational talent. That being said, I have paid particular attention to the singing that I've seen from my colleagues on both sides of the Atlantic and I have some general insights to share with you all, which you might want to keep in mind the next time you think about characterization for role preparation. (Phew, that's a tongue twister!)
Anyway, I have watched various professional and non-professional colleagues from Germany and the USA, and I have noticed two distinct camps of acting training that are making themselves evident from the performances I've witnessed. The German singers I've seen have managed to maintain (no matter what the dramatic situation was) a sort of naiviete in the portrayal of their characters while singing. This, I believe, comes from their in-depth understanding of each word that they sing.
And, I don't just mean what we American singers think of (I can hear you saying to yourself- 'But I've done the word-for-word translation already!') in terms of translating from the Nico Castel books each word into English and then copying down the IPA. Memorizing strings of archaic translations that end up looking like Shakespearian verse are NOT going to help make your acting more truthful. And, this is exactly what the majority of our German counterpoints have figured out, and have used to their advantage in their portrayals. They realize that they must have as much of a sense of the words they're singing as they would if they were speaking their own native tongue. For example, Diana Damrau certainly doesn't have to speak fluent French to sing her role in 'Le Comte Ory' well, but she does need to have an almost native-speaker familiarity with the thousand-some words she sings in order to make her portrayal believeable. So, that actually means that you only need to have the vocabulary mastered that you will be using in your singing to use this method. (Yes, you can breathe a sigh of relief now that you've realized that you don't have to speak German fluently just to sing the Komponist! Although...it might help in the long run....)
As regards us Americans, I have found that on the whole, in terms of our acting, it is much more generic and therefore loses something in terms of believeability. It's as if we use the 4th wall in our singing performances for two reasons: either we are scared of the audience members and interacting with them, or we are purposefully ignoring them because we think it's the right thing to do. These two approaches yield a rather static effect, and one which, unfortunately, does not retain the truthfulness of the approach that I've found in Germany.
This is just a personal hypothesis, but I believe that this attitude in American versus German singers can be traced to different cultural perceptions of the definition of 'performing' and what is considered 'socially appropriate'. Whereas in America people are normally very open with one another upon first meeting, it would be considered (normally) quite rude to be open to someone to whom one was never actually introduced (as is asked of the performer when performing for an audience), and therefore, we as singers, become shy (or scared of our audience) or, choose to purposefully ignore them (making it difficult for them to relate to what we're doing on a deeper level than finding it merely pretty, although easy for us to survive with our sense of propriety intact after a performance is finished). However, it's we the singers who are losing out.
Contrastingly, in Germany there is a tangible expectation from the audience: they want to be part of the experience and they want to be entertained. Therefore, it is easier for the performer to allow this conversational and intimate dialog to happen between themselves and the audience (even if they don't know anyone to whom they're singing) because it is expected that the singer interact with the audience members on a more 'personal' and 'individual' level. Thereby altogether eliminating the 4th wall. Hence, this cultural expectation carries over to all performances given by singers trained in this way, thereby providing them with a expert platform from which to build their relationship to the audience, no matter where they're performing (and what the cultural expectations of that country might be).
Let's face it, this all comes down to one common principle which we know to be true the world over: people like to relate to one another, and we as performing artists, have the ability to do that with our audience members every time that we step on stage. So, keeping this in mind, even if you weren't schooled in an interactive performance method from the very beginning of your training, you are still in control of every performance. Whether or not you'll be aware of your openness to the audience and your subsequent lukewarm or exuberant reception based on which path you've chosen, is up to you.